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多字段 java对象排序
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public class ReflexUtil {
static Logger logger = LoggerFactory.getLogger(ReflexUtil.class);
//getMethod
static public Object invokeMethod(String propertiesName, Object object) {
try {
if(object==null) return null;
if (!propertiesName.contains(".")) {
String methodName = "get"+getMethodName(propertiesName);
Method method = object.getClass().getMethod(methodName);
return method.invoke(object);
}
String methodName = "get"+getMethodName(propertiesName.substring(0,propertiesName.indexOf(".")));
Method method = object.getClass().getMethod(methodName);
return invokeMethod(propertiesName.substring(propertiesName.indexOf(".")+1), method.invoke(object));
} catch (Exception e) {
logger.error(e.toString(), e);
return null;
}
}
private static String getMethodName(String fildeName) {
byte[] items = fildeName.getBytes();
items[0] = (byte) ((char) items[0] - 'a' + 'A');
return new String(items);
}
public static void main(String args[]) {
Video video = new Video();
Album album = new Album();
album.setAlbumId(346l);
video.setAlbum(album);
video.setVideoId(126l);
System.out.println(ReflexUtil.invokeMethod("album.albumId", video));
}
}
public
class
CompareUtil {
//sort 1正序 -1 倒序 filed 多字段排序
public
static
<t> Comparator createComparator(
int
sort, String... filed) {
return
new
ImComparator(sort, filed);
}
public
static
class
ImComparator
implements
Comparator {
int
sort =
1
;
String[] filed;
public
ImComparator(
int
sort, String... filed) {
this
.sort = sort == -
1
? -
1
:
1
;
this
.filed = filed;
}
@Override
public
int
compare(Object o1, Object o2) {
int
result =
0
;
for
(String file : filed) {
Object value1 = ReflexUtil.invokeMethod(file, o1);
Object value2 = ReflexUtil.invokeMethod(file, o2);
if
(value1 ==
null
|| value2 ==
null
) {
continue
;
}
if
(!(value1
instanceof
Integer) || !(value1
instanceof
Integer)) {
continue
;
}
int
v1 = Integer.valueOf(value1.toString());
int
v2 = Integer.valueOf(value2.toString());
if
(v1 == v2)
continue
;
if
(sort ==
1
) {
return
v1 - v2;
}
else
if
(sort == -
1
) {
return
v2 - v1;
}
else
{
continue
;
}
}
return
result;
}
}
public
static
void
main(String args[]) {
LabelAlbum label1 =
new
LabelAlbum();
label1.setLabelId(
1
); label1.setSequnces(
1
);
LabelAlbum label2 =
new
LabelAlbum();
label2.setLabelId(
1
);label2.setSequnces(
2
);
LabelAlbum label3 =
new
LabelAlbum();
label3.setLabelId(
3
); label3.setSequnces(
4
);
LabelAlbum label4 =
new
LabelAlbum();
label4.setLabelId(
3
);label4.setSequnces(
3
);
LabelAlbum label5 =
new
LabelAlbum();
label5.setLabelId(
4
);label5.setSequnces(
2
);
List<labelalbum> list =
new
ArrayList<labelalbum>();
list.add(label1);
list.add(label2);
list.add(label3);
list.add(label4);
list.add(label5);
Collections.sort(list, CompareUtil.createComparator(
1
,
"labelId"
,
"sequnces"
));
for
(
int
i =
0
; i < list.size(); i++) {
LabelAlbum labelAlbum=list.get(i);
System.out.println(
"labelId:"
+labelAlbum.getLabelId()+
" sequence："
+labelAlbum.getSequnces());
}
}
}</labelalbum></labelalbum></t>
